Spray oil



Dec. 19,1939. U, r 2,183,781

I SPRAY OIL l iled Jan. 27, 1956 SL1 6H OXIDATION NUMBER I o EXTRACT-S *VOLUMN PER CENT J'KB. 1 2. v

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Patented Dec. 19, 1939 UNITED STATES PATENT OFFICE 1 SPRAY on.

Ulric B. Bray,

signor to Union Los Angeles,

Application January 27, 1936, Serial No. 60,941

12 Claims.

The invention relates to spray oils produced from petroleum and adapted to the preparation of emulsions and the like for the production of insecticides and fungicides in general, particularly for use of plant insecticides with special reference to the control ofcitrus pests of which the scales are important examples.

The principal, object of the invention is to produce a spray oil. of high toxic power which is non-injurious to tender foliage and fruit. It has in the past been a desideratum to produce such spray oils having non-phytocidal properties, but

in general when these have been obtained the insecticidal value has not been sufliciently high.

I have discovered that it is possible to treat naphthenic type petroleum stocks so as to produce non-phytocidal oils which retain certain types of.

low A. P. I. gravity materials largely aromatic in character which are good insecticides but are non-toxic to plant life, at least in the proportions retained; whereas heretofore these materialshave been removed with strong sulfuric acid. In

other words, not all materials containing aromatic or other structures which can be attacked and removed by, strong sulfuric acid are necessarily injurious to plants. Such materials which are non-injurious to plants but can be removed by strong sulfuric acid are at the same time more effective as insecticides than are the high gravity more paraflinic compounds which are not at tacked by strong sulfuric acid'or the like and commonly used as insecticidal spray oils for fruit and plant life. The present products are to be obtained from naphthenic type petroleums, it being difficult, if not substantially impossible, to obtain them from paraflinic type oils.

The present invention, therefore, resides in an oil producible from naphthenic type petroleum stocks, and in a process for producing such oil, wherein the sulfonatable residue (1. e., that proportion which may be attacked and removed by sulfuric acid by a certain well known method herein described), is somewhat greater. than about 20%, and at the same time is not toxic to tender fruit and foliage in the concentrations in which this general type of oil is employed, while being of high insecticidal value for scale and corresponding fraction) of the oils of very low sulfonatable residue. These high oxidation number materials are less than about 100 on the Sligh scale (hereinafter defined) as against over 250 for the stocks from which these oils are made.

Thus, the oxidationv numbers and the percentage of sulfonatable residues together constitute a definition of the oils of this invention.

Otherwise stated, the invention resides in a mineral spray oil produced by a sufficiently careful treatment of the naphthenic type stock to remove practically all of the unsaturated and readily reactive components such as the olefinic. type of unsaturates, while leaving a product nontoxic to plants although containing appreciable quantities of low A. P. I. gravity aromatic materials (e. g. heavier than 18 A. P. I. gravity) which greatly increase the insecticidal characteristics. These oils at the same time possess a higher, though not excessive, overall Sligh oxidation number (above about 20 and below about 30) and a higher sulfonatable residue value than those commonly known at present as non-phytocidal mineral spray oils of high unsulfonatable residue wherein more than about 90% is composed of unsulfonatable (highly paraflinic) constituents by the de Ong test hereinafter described. Such oils are heavier than conventional spray oils, having an A. P. I. gravity ordinarily below'2'1 and above 23.

In carrying out this'invention, the stock employed is subjected to a carefully controlled acid treatment to avoid excessive removal of materials in the sulfuric acid while at the same time removing substantially all of the readily reactive materials which include substantially all of the unsaturated materials including the oleflnic types, though not necessarily all unsaturated materials. Thus, a low parafilnicity stock high in aromatic and hvdroaromatic or naphthenic materials may be treated, preferably in a plurality of treatments. The temperature is controlled so as not to exceed about 100 F. This treatment may commence at about F. to F. and be allowed to rise during the various steps but not toexceed F. or F.

Thus, I have treated a spray oil stock produced from a San Joaquin Valley crude, such as Poso T Creek, Coalinga or McKittrick crude as an overhead distillate having the following characteristics as typical:

Viscosity, Saybolt UnivrsaL- 106 sec. at 100 F. Viscosity gravity constant- 0.892

A. P. I. gravity at, 60 F... 21.4 Flash point 310 F.

. Pour point Minus 30 F, Sligh oxidation number 180 De Ong number 63.8

This treatment comprised three successive acid treatments, each of which employed 25 pounds 98% sulfuric acidperbarrel, or a total of 75 pounds per barrel at than about 100 F. In order to improve color, about 3% by weight bfclay was employed in each temperatures slightly less instance. The acid treatment may also be efiected in two operations using a little more acid totalling about 80 to 85 pounds of acid in two equal dumps, and similar results may be effected in one operation with still moreacid, or about 100 pounds of acid per barrel, but the three stage treatment is preferred both because of greater acid economy and preferable results. In any event, the same temperature control is maintained.

The product obtained was a desirable spray oil typical of the present invention having the following characteristics:

Viscosity, Saybolt Universal--- 91 sec. at 100 F.

Viscosity gravity constant 0.874

A. P. I. gravity at 60 F 24.2

Flash point 305 F.

Pour point Below -80 F. Sligh oxidation number to 27 De Ong number 77.1

Viscosity, Saybolt Universal 93 sec. at 100 F.

Viscosity gravity constant 0.848

A. P. I. gravity at 60 F 27.9 Flash point 310 F. Pour point 30 F. Sligh oxidation number 19 De Ong number 92.3

Specifications for the Sligh oxidation test are defined in A. S. T. M. Proceedings, vol. 27 (1927) Part I, page 461. Briefly, 10 grams of oil are placed in an oxygen fllledflask which is sealed at atmospheric pressure and immersed in an oil bath at 200 C. for 2% hours. Following cooling, the oil is diluted to 100 m. l. with standard A. S. T. M. precipitating petroleum naphtha, shaken and allowed to precipitate while standing for 1 hour at 25 C.:2. The residue is filtered out and weighed.

The percentage thereof multiplied by 100is the I Sligh oxidation number.

Inasmuch as de Ong" number has come to be commonly used as an indication of the unsulphonatable residue of an oil, de Ong number is here used for the same purpose. However, whereas unsulphonatable residue has commonly been accepted in the past as a measure of the nhytocidal and insecticidal characteristics or an Oil, such an application is not so used nor accepted here, as will become apparent presently. The de Ong number may be definedas the unsulphonatable percentage residue of an oil as determined by specifications for such a test as given in Industrial and Engineering Chemistry, vol. 18 (1926) page 175. Briefly, the oil is treated with sulphuric acid exactly 37 normal (100%) in a water bath at to CP -ordinarily at 210 to 212 F.for a period of (me hour, 20 c. c. of the above acid being added to 5 c. c. of oil in two dumps in a Babcock cream test bottle, the mix being agitated every 10minute's. After phase separation, the percentage of unsulphonated residue is the do One In the light of my discoveries it appears that the de Ong test for spray oils is largely a test for aromatic nuclei which can be sulfonated with 100% sulphuric acid at 212 F. (100- C.) as well as a test for react and readily acid soluble compounds, and thathe presence in a compound of an aromatic nuc eus which can be sulfonated by strong acid at superatmospheric temperature is not .a criterion of the phytocidal characteristics of the compound. In other words, there are two general types of compounds soluble'in sulphuric acid in the de Ong test with 100% acid at 212 F. (100 C.), namely the unsaturates or readily reactive materials and the aromatic compounds or less readily reactive materials. Only those which can be classified as unsaturates or otherwise readily chemically reactive, appearto be strictly toxic to the plant.

According to the present invention the chemi cally reactive (phytocidal) materials are removed and the greater proportion of the less reactive or relatively non-reactive (non-phytocidal) or aromatic components or all of such relatively nonreactive -or aromatic components are allowed to remain in the oil, even though some of these nonphytocidal components are characterized by relatively low de Ong numbers and low A. P. I. gravity.

When I use the term chemically reactive I refer to those materials which are injurious to plants when used thereon as spray oils either in the well known and customary form of emulsions or in any other form suitable for application.

Various methods of producing emulsions for these purposes are well known in the art. Thus, according to one approved practice, a to 2% emulsion of the spray oil is prepared using ammonium caseinate as an emulsifier,'and this emulsion is sprayed upon the citrus trees and their fruit, the emulsion being such as to break easily and leave a film of 011. By such an application of the oil of the present invention, a complete kill of scale has resulted and after many weeks no objectionable influences upon either foliage or fruit have been observable. These tests have been conclusive, although contrary to previously approved theories regarding de Ong values.

In order better to, visualize the constitution of the spray oil of the present invention the accompanying drawing is furnished. In the drawing:

Fig. 1 shows curves representing the averages of Sligh oxidation numbers of a, series of fractions averaging about 5% each, and indicative of a composite of oils of the type of the present invention in comparison with similar series of fractions of conventional spray oils having high overall de Ong numbers (above 90);

Fig. 2 shows similar curves plotting the de Ong numbers of these oil types; and

Fig. 3 shows similar curves plotting the A. P. I. gravity of these same types-of oils.

- Spray oils of the new type have de Ong numbers less than about 80 and those illustrated have de Ong numbers lying between 75 and 80. Such oils however, may be 'prepared wlth de Ong numbers extending even below 75', but probably not falling below 70, and still be useful for the present purpose. This distinguishes from the type of high de Ong oils illustrated wherein the de Ong number runs around 93. As indicated by the curves of Fig. 2, the average conventional high de Ong oil contains fractions ranging from about 36 de Ong number to about 99 de Ong have a relatively number, the great bulk of the materials being 76 ventional type (high 55 tests.

above 90. On the other hand, the new oil of the present invention contains materials ranging as low as 6 de Ong number up to as high as 96 de Ong number, with the average far below 90.

In segregating various fractions of the oils tested in order to determine the de Ong numbers,

,-Sligh ozidation numbers and A. P. I. 'gravities of the various fractions, the oil was subjected to a series of extractions with appropriate solvents starting at low temperatures andrising through a fairly wide temperature range as successive extractions were made. Thus. solvent extraction with sulphur dioxide was employed in some cases, starting at -25 F. and working up to 125 F;

u about 150 volume percent of solvent being employed in each extraction. Again liquid sulphur dioxide was used at the lower temperatures (around -25 F. to -30 F.) in about the same proportions, but liquid sulphur dioxide-benzene mixtures (75% sulphur dioxide) were employed in amounts of about 100 volume percent of solvent at temperatures extending above about 75 F. In this manner, a large series of fractions of successively varying aromatic content were obtained, the content of the aromatic and unsatuto develop in the curves for the Sligh oxidation number, especially in those fractions having the higher numbers, but for the most part these were within the range of experimental error in conducting the tests or attributable to other irregular 0 factors accompanying. the tests.

Referring to the de-Ongconstitution of the 'present 011 as compared with the conventional high de Ong oil, having Fig. 2 in mind, it will be noted that less than 10% of the standard or conde Ong) oil fallsbelow 85 de Ong number (85% unsulphonatable residue),

whereas with the new type oil around 50% falls below 85 de Ong number. .Since these oils-thus possess widely different characteristics in so far 50 as de Ong number, Sligh oxidation number and gravity are,concerned, and since according to the. commonly accepted theory of de Ong number, they would have been classed as toxic to plant ..life, these oils were subjected to. comparative foliage, both" oils tested 100% negative as regards plant injury. As a further check on toxicity the oils were tested on geraniums, which are very tender and respond very quickly. In this series of tests the new spray oil of the present invention. tested about 99% negative on the geranlums. as

- against 100% for the high-dc Ong oil. This'was L despite the fact that in the new oil there is a much larger percentage of material, which when segregated has a positive toxic action upon g'eraniums, than there is in the conventional high de on; oil. 1

As has been indicated, the new oil here dis- 70 closed is'a type oil representing the general char- 'acter of oils of this invention. Such oils have a .de Ong number lower than about 80, that is, the sulphonatableresidue exceeds about 20%,less than .about 5% having a Sligh oxidation number above 75 about 80,.thereheing very little if any content when used to\ treat citrus fruits and over about 100 Sligh. Although the oil of this invention is non-toxic to plant life, it nevertheless contains nearly 20% of materiaisof higher specific gravity than the heaviest material of the conventionalhigh de Ong oil of about the same boiling range and also 20% of materials having lower de Ong ngrfibers than the lowest corresponding fractio of the high de Ong. oil. .At

the same time, 1 to 20% is higher than about a lo 30 in Sligh oxidation number, while all its frac-j' tions possess a Sligh oxidation number higher than about (although not over about5% is over-80 Sligh number) and 80% of the; oil

averages about 20. Sligh number. The conventional high de Ong spray oil, on the other hand, contains about 90% of materials having a Sligh oxidation number less than about 15, and less 1 than about 5% has a Sligh number materially over 20. The overall Sligh oxidation numbers of these new oils will fall between about and about Y 30 within the range of experimental errors.

It is of outstanding significance that the oil of the present invention has non-toxicity value for citrus fruit and foliage and similar plant life, commercially equal to that of, the conventional high de Ong oil in spite of the fact that its overall oxidation number is higher, and that the oxidation number of its corresponding percentage 9 fractions is lower than that of the conventional high de Ong spray oil. Heretofore, it has been believed that non-phytocidal spray oils must have a de Ong number at least as high as about 90 and certainly much above 80, whereas my discoveries have shown that properly prepared materials may have de Ong numbers materially less than 80 and. possess greater insecticidal value without being more toxic to the plant life upon which they are designed to be used. I

Looking at the oil content from the viewpoint of gravity, the new oilcontains over 15% of materials heavier than 18 A. P. I. gravity, whereas a standard or conventional high de Ong oil contains substantially nothing below 18 A. P. I. gravity. Again, where the conventional oil contains only 20% to of materials below about 28 A. P.I. gravity the new oil contains to of such heavier materials or nearly twice as much thereof. Whereas, such percentages of' materials of greater specific gravity have heretofore been considered to'render these products useless as spray oils, it has now been discovered that it is the type of material that controlsnot its gravity or de Ong number.

The present oils are distinguished from conventional r'ed? oils (acid treated oils) ,in that such red oils have considerably higher oxidation numbers than the oils of'this invention. Thus, said red oils will in general have overall Sligh oxidation numbers in excess of about 50, and portions thereof will run as high as 150 oxidation number or even higher. Again, a content oils ofhigh de-Ong number now commonly in use and herein mentioned.

' pressure which may approximate 850 lbs. per sq.

in. (or at similar temperatures and pressures within cracking practices well known in the art), suilicient fresh gas oil being added to the cycle stock as cracking proceeds to maintain the feed to the charging pumps. The cracked product may then be fractionated to produce a suitable spray oil stock such as one having an A. P. I. gravity at 60 F. of 11 to and viscosity Saybolt Universal of 50-60 at '100F. and a de Ong number of 15 to 50 with an average boiling point of about 600 F. This material is then subjected to an acid treatment similar to the multistage treatment above described in order to remove the more reactive aromatic and unsaturated constituents. Thus, it may betreated with lbs. of concentrated sulphuric acid as previously described in each of three dumps, or if necessary, it may be treated with equal amounts in each of four dumps, or in afewer number of dumps totalling 75 to 100 lbs. of acid per bbl. to be followed inthe usual way by neutralization with caustic, water washing, and treatment with clay (e. g., 3% of Death Valley clay), as well understood in the art.

Such an oil may have a de Ong number of approximately and when applied as a spray oil, emulsion or otherwise, will evaporate quite readily so that after it has efiectively killed pests upon plant life it will then entirely evaporate thereby reducing the possibility of endangering the plant by reason of prolonged contact therewith. Again, this oil may be subjected to a more severe acid treatment in order to raise the de Ong number to some higher value desired such as 50 or 60. Overall Sligh oxidation numbers of these oils will run from 25 to 50. Again, these oils may be blended with a conventional spray oil of high de Ong number or a white medicinal oil, such as one having a de Ong number of 98, whereby the de Ong number of the total product will lie within the range of between 50 to 80, for example, and the Sligh oxidation number from 20 to 40. Such a blended oil will release more volatile, aromatic constituents having low de Ong numbers after a time sufficient to efiect a complete kill, thereby allowing the high de Ong number materials (highly paraflim'c materials) to remain upon the plant or fruit for a long period of time in accord ance with the prevailing practice.-

According to this modification, it is apparent that naphthenic type of oils may be prepared by resorting to cracking whereby low viscosity aromatic spray oil fractions may be obtainedhaving comparatively high volatility and lowfide Ong number whereby they are adapted to a quick kill of plant pests without injuring the plant, and that the benefits of prolonged contact with the more paraflinic materials may be obtained by blending highly insecticidal relativelymore volatile materials with less volatile highly paraflinic materials. The characteristics of naphthenic fractions so produced by cracking paraflinic or naphthenic type oils and subsequently acid treatoils ing for use according to the present invention will in general fall'within the following ranges:

Viscosity Saybolt Universal to 90 sec. at 100 1. A. P. I. gravity at 60 F- 12 to 22 Flash point 240 F. to 310 1''. Pour point Below 20 F. Sligh oxidation number 25 to .50 De Ong number 25 to 75 Blends of these materials with high de Ong materials may be prepared by combining in various proportions to obtain materials within the following ranges:

It is to be understood that the disclosures hereof are merely illustrative of the generic invention and are not to be taken as limiting except as required by the prior art and the appended claims.

I claim: 1. A spray oil in the form of an extracted petroleum fraction having an A. P. I. gravity in the vicinity of 23 to 27, an overall Sligh oxidation number in excess of about 20 of which approximately 80% possesses a Sligh oxidation number between 15 and 25 and averaging about 20, the oil having .a de Ong number less than about 80.

2. vA mineral spray oil from which chemically reactive materials have been largely removed by solvent extraction, the oil containing aromatic constituents possessing high-insecticidal properties, the oil having an overall Sligh oxidation number between about 20 and 30, about 80% of the oil having a Sligh oxidation number between about 15 and 25 and the oil'having a de Ong number less than about 80.

3. A spray oil in the form or an extracted petroleum fraction, about 15% of whose content has a-Sligh oxidation number over 25 but less han 5% has a Slighoxidation number over about 80, and about 80% has a Sligh oxidation number between about 15 and about 25 and averaging about 20.

4. A non-phytocidal mineral spray oil about 15% of whose content has a Sligh oxidation number between about 25 and about 100 and about 80% of whose content has a Sligh oxidation number between about 15 and about 25, and averaging about 20, said oil number below about 80.

5. A non-phytocidal mineral spray oil free from readily reactive materials but containing aromatic materials, only about 15% to 20% of whose content is heavier than 18' A. P. I. and only about 30% is heavier than 24 A. P. I., the oil having an overall Sligh oxidation number between about 20 andabout and a de Ong number below about 85.

6. A non-phytocidilj mineral spray oil gphtain- 'ing aromatic materials but substantially free from =readily reactive unsaturates, the oil having an overall de Ong number below about 80 and having a de Ong having about 20% of its content below about de Ong with about 5% as low as 10 de Ong,

the overall Sligh number of the oil being around 23 to 28, with about 80% averaging about 20 Sligh number, about 15% lying above about 25,

not over 5% above about 80, and substantially no content-above 100 Sligh oxidation number.

'7. A naphthenic type mineral spray oil free from reactive materials toxic to plants and containing aromatic materials having highly insecticidal properties, the oil having an overall Sligh oxidation number above about and below about and having a de Ong number below about 80 and above about 30.

8. A non-phytocidal mineral spray oil produced from a'naphthenic type material and containing aromatic constituents, the oil having an A. P; I. gravity between about 23 and 27, an

overall Sligh oxidation number between about 23 and 28, and being substantially .free from constituents having Sligh oxidation numbers as high as 100, and containing not more than a.

few percent of constituents having a Sligh oxidation number as low as 15.

9. A non-phytocidal mineral spray oil containing aromatic fractions havinghighly insecticidal value, the oil having an overall Sligh oxidation number between 20 and 30, an A. P. I, gravity between about 23 and 28, and viscosity Saybolt Universal at 100 'F. above about seconds and below about 100 seconds. a

10. An oil according to claim.9 having a de Ong number below about 80.

'11. A non-phytocidal mineral oil having an A. P. I. gravity between about 23 and 27 and having an overall Sligh oxidation number above' 20 and below about 50, the oil containing substantially no constituents having a Sligh oxidation number above 100, the Sligh oxidation number of each successive 5% fraction separable by solvent fractionation of about of the total oil being'above 15 and averaging above about 18 and below about 30, and about half of the remaining 20% of the oil having Sligh oxidation numbers above 30.

12. A non-phytocidal'mineral spray oil having an overall Sligh oxidation number above .20 and below about 50, 'the oil containing substantially no constituents having a Sligh oxidation number above 100, the Sligh oxidation number of about 80% of the oil being above 15 and averaging above about 18 and below 50, and less than about half of the remaining 20% having a Sligh oxida- 25 tion number above 50;

ULRIC B. BRAY. 

